var CryptoJS = require('./core');

(function(Math) {
  // Shortcuts
  var C = CryptoJS;
  var C_lib = C.lib;
  var WordArray = C_lib.WordArray;
  var Hasher = C_lib.Hasher;
  var C_algo = C.algo;

  // Constants table
  var T = [];

  // Compute constants
  (function() {
    for (var i = 0; i < 64; i++) {
      T[i] = (Math.abs(Math.sin(i + 1)) * 0x100000000) | 0;
    }
  }());

  /**
   * MD5 hash algorithm.
   */
  var MD5 = C_algo.MD5 = Hasher.extend({
    _doReset: function() {
      this._hash = new WordArray.init([
        0x67452301, 0xefcdab89,
        0x98badcfe, 0x10325476
      ]);
    },

    _doProcessBlock: function(M, offset) {
      // Swap endian
      for (var i = 0; i < 16; i++) {
        // Shortcuts
        var offset_i = offset + i;
        var M_offset_i = M[offset_i];

        M[offset_i] = (
          (((M_offset_i << 8) | (M_offset_i >>> 24)) & 0x00ff00ff) |
          (((M_offset_i << 24) | (M_offset_i >>> 8)) & 0xff00ff00)
        );
      }

      // Shortcuts
      var H = this._hash.words;

      var M_offset_0 = M[offset + 0];
      var M_offset_1 = M[offset + 1];
      var M_offset_2 = M[offset + 2];
      var M_offset_3 = M[offset + 3];
      var M_offset_4 = M[offset + 4];
      var M_offset_5 = M[offset + 5];
      var M_offset_6 = M[offset + 6];
      var M_offset_7 = M[offset + 7];
      var M_offset_8 = M[offset + 8];
      var M_offset_9 = M[offset + 9];
      var M_offset_10 = M[offset + 10];
      var M_offset_11 = M[offset + 11];
      var M_offset_12 = M[offset + 12];
      var M_offset_13 = M[offset + 13];
      var M_offset_14 = M[offset + 14];
      var M_offset_15 = M[offset + 15];

      // Working varialbes
      var a = H[0];
      var b = H[1];
      var c = H[2];
      var d = H[3];

      // Computation
      a = FF(a, b, c, d, M_offset_0, 7, T[0]);
      d = FF(d, a, b, c, M_offset_1, 12, T[1]);
      c = FF(c, d, a, b, M_offset_2, 17, T[2]);
      b = FF(b, c, d, a, M_offset_3, 22, T[3]);
      a = FF(a, b, c, d, M_offset_4, 7, T[4]);
      d = FF(d, a, b, c, M_offset_5, 12, T[5]);
      c = FF(c, d, a, b, M_offset_6, 17, T[6]);
      b = FF(b, c, d, a, M_offset_7, 22, T[7]);
      a = FF(a, b, c, d, M_offset_8, 7, T[8]);
      d = FF(d, a, b, c, M_offset_9, 12, T[9]);
      c = FF(c, d, a, b, M_offset_10, 17, T[10]);
      b = FF(b, c, d, a, M_offset_11, 22, T[11]);
      a = FF(a, b, c, d, M_offset_12, 7, T[12]);
      d = FF(d, a, b, c, M_offset_13, 12, T[13]);
      c = FF(c, d, a, b, M_offset_14, 17, T[14]);
      b = FF(b, c, d, a, M_offset_15, 22, T[15]);

      a = GG(a, b, c, d, M_offset_1, 5, T[16]);
      d = GG(d, a, b, c, M_offset_6, 9, T[17]);
      c = GG(c, d, a, b, M_offset_11, 14, T[18]);
      b = GG(b, c, d, a, M_offset_0, 20, T[19]);
      a = GG(a, b, c, d, M_offset_5, 5, T[20]);
      d = GG(d, a, b, c, M_offset_10, 9, T[21]);
      c = GG(c, d, a, b, M_offset_15, 14, T[22]);
      b = GG(b, c, d, a, M_offset_4, 20, T[23]);
      a = GG(a, b, c, d, M_offset_9, 5, T[24]);
      d = GG(d, a, b, c, M_offset_14, 9, T[25]);
      c = GG(c, d, a, b, M_offset_3, 14, T[26]);
      b = GG(b, c, d, a, M_offset_8, 20, T[27]);
      a = GG(a, b, c, d, M_offset_13, 5, T[28]);
      d = GG(d, a, b, c, M_offset_2, 9, T[29]);
      c = GG(c, d, a, b, M_offset_7, 14, T[30]);
      b = GG(b, c, d, a, M_offset_12, 20, T[31]);

      a = HH(a, b, c, d, M_offset_5, 4, T[32]);
      d = HH(d, a, b, c, M_offset_8, 11, T[33]);
      c = HH(c, d, a, b, M_offset_11, 16, T[34]);
      b = HH(b, c, d, a, M_offset_14, 23, T[35]);
      a = HH(a, b, c, d, M_offset_1, 4, T[36]);
      d = HH(d, a, b, c, M_offset_4, 11, T[37]);
      c = HH(c, d, a, b, M_offset_7, 16, T[38]);
      b = HH(b, c, d, a, M_offset_10, 23, T[39]);
      a = HH(a, b, c, d, M_offset_13, 4, T[40]);
      d = HH(d, a, b, c, M_offset_0, 11, T[41]);
      c = HH(c, d, a, b, M_offset_3, 16, T[42]);
      b = HH(b, c, d, a, M_offset_6, 23, T[43]);
      a = HH(a, b, c, d, M_offset_9, 4, T[44]);
      d = HH(d, a, b, c, M_offset_12, 11, T[45]);
      c = HH(c, d, a, b, M_offset_15, 16, T[46]);
      b = HH(b, c, d, a, M_offset_2, 23, T[47]);

      a = II(a, b, c, d, M_offset_0, 6, T[48]);
      d = II(d, a, b, c, M_offset_7, 10, T[49]);
      c = II(c, d, a, b, M_offset_14, 15, T[50]);
      b = II(b, c, d, a, M_offset_5, 21, T[51]);
      a = II(a, b, c, d, M_offset_12, 6, T[52]);
      d = II(d, a, b, c, M_offset_3, 10, T[53]);
      c = II(c, d, a, b, M_offset_10, 15, T[54]);
      b = II(b, c, d, a, M_offset_1, 21, T[55]);
      a = II(a, b, c, d, M_offset_8, 6, T[56]);
      d = II(d, a, b, c, M_offset_15, 10, T[57]);
      c = II(c, d, a, b, M_offset_6, 15, T[58]);
      b = II(b, c, d, a, M_offset_13, 21, T[59]);
      a = II(a, b, c, d, M_offset_4, 6, T[60]);
      d = II(d, a, b, c, M_offset_11, 10, T[61]);
      c = II(c, d, a, b, M_offset_2, 15, T[62]);
      b = II(b, c, d, a, M_offset_9, 21, T[63]);

      // Intermediate hash value
      H[0] = (H[0] + a) | 0;
      H[1] = (H[1] + b) | 0;
      H[2] = (H[2] + c) | 0;
      H[3] = (H[3] + d) | 0;
    },

    _doFinalize: function() {
      // Shortcuts
      var data = this._data;
      var dataWords = data.words;

      var nBitsTotal = this._nDataBytes * 8;
      var nBitsLeft = data.sigBytes * 8;

      // Add padding
      dataWords[nBitsLeft >>> 5] |= 0x80 << (24 - nBitsLeft % 32);

      var nBitsTotalH = Math.floor(nBitsTotal / 0x100000000);
      var nBitsTotalL = nBitsTotal;
      dataWords[(((nBitsLeft + 64) >>> 9) << 4) + 15] = (
        (((nBitsTotalH << 8) | (nBitsTotalH >>> 24)) & 0x00ff00ff) |
        (((nBitsTotalH << 24) | (nBitsTotalH >>> 8)) & 0xff00ff00)
      );
      dataWords[(((nBitsLeft + 64) >>> 9) << 4) + 14] = (
        (((nBitsTotalL << 8) | (nBitsTotalL >>> 24)) & 0x00ff00ff) |
        (((nBitsTotalL << 24) | (nBitsTotalL >>> 8)) & 0xff00ff00)
      );

      data.sigBytes = (dataWords.length + 1) * 4;

      // Hash final blocks
      this._process();

      // Shortcuts
      var hash = this._hash;
      var H = hash.words;

      // Swap endian
      for (var i = 0; i < 4; i++) {
        // Shortcut
        var H_i = H[i];

        H[i] = (((H_i << 8) | (H_i >>> 24)) & 0x00ff00ff) |
          (((H_i << 24) | (H_i >>> 8)) & 0xff00ff00);
      }

      // Return final computed hash
      return hash;
    },

    clone: function() {
      var clone = Hasher.clone.call(this);
      clone._hash = this._hash.clone();

      return clone;
    }
  });

  function FF(a, b, c, d, x, s, t) {
    var n = a + ((b & c) | (~b & d)) + x + t;
    return ((n << s) | (n >>> (32 - s))) + b;
  }

  function GG(a, b, c, d, x, s, t) {
    var n = a + ((b & d) | (c & ~d)) + x + t;
    return ((n << s) | (n >>> (32 - s))) + b;
  }

  function HH(a, b, c, d, x, s, t) {
    var n = a + (b ^ c ^ d) + x + t;
    return ((n << s) | (n >>> (32 - s))) + b;
  }

  function II(a, b, c, d, x, s, t) {
    var n = a + (c ^ (b | ~d)) + x + t;
    return ((n << s) | (n >>> (32 - s))) + b;
  }

  /**
   * Shortcut function to the hasher's object interface.
   *
   * @param {WordArray|string} message The message to hash.
   *
   * @return {WordArray} The hash.
   *
   * @static
   *
   * @example
   *
   *     var hash = CryptoJS.MD5('message');
   *     var hash = CryptoJS.MD5(wordArray);
   */
  C.MD5 = Hasher._createHelper(MD5);

  /**
   * Shortcut function to the HMAC's object interface.
   *
   * @param {WordArray|string} message The message to hash.
   * @param {WordArray|string} key The secret key.
   *
   * @return {WordArray} The HMAC.
   *
   * @static
   *
   * @example
   *
   *     var hmac = CryptoJS.HmacMD5(message, key);
   */
  C.HmacMD5 = Hasher._createHmacHelper(MD5);
}(Math));

module.exports = CryptoJS.MD5;
